LiSICon Membrane Flow Control for LiOH Production From Impure Feed
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Solution Overview
Problem
Existing lithium-ion battery recycling processes struggle to economically recover lithium hydroxide (LiOH) from spent batteries due to the high reactivity of lithium, impurities that damage LiSICon membranes, and the high energy and water consumption required for thermal separation from natural deposits, leading to short membrane lifetimes and inefficient processes.
Innovation Solution
A process using a LiSICon membrane in an electrochemical cell with controlled flow conditions, including a flat membrane and specific overflow velocities, allows for the continuous production of lithium hydroxide from impure lithium-containing waters, maintaining membrane integrity and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If thermal separation processes are used to extract lithium from natural deposits, then lithium hydroxide can be produced, but the process consumes high amounts of energy and water
Solution Approach 1:
The patent replaces thermal separation processes with electrochemical membrane separation using LiSICon membranes. Instead of using high-temperature thermal methods to separate lithium from brine, the invention employs an electrochemical cell with a lithium-selective ion-conducting membrane that uses electrical potential to drive lithium ions across the membrane, thereby eliminating the need for energy-intensive thermal processing while achieving the same separation objective
Solution Approach 2:
The invention changes the separation mechanism from thermal to electrochemical by applying electrical potential across the membrane. This parameter change allows lithium extraction to occur at ambient temperatures rather than requiring high-temperature thermal processes, significantly reducing energy consumption while maintaining effective lithium separation from brine
2Quantity of substance
If LiSICon membranes are used for lithium separation, then lithium can be recovered from spent batteries, but impurities in the feed cause membrane damage and short lifespan
Solution Approach 1:
The patent implements preliminary filtration and purification steps before the feed enters the electrochemical cell. Impurities such as particulates, organics, and other ions are removed in advance through filtration systems and chemical treatment, preventing these substances from reaching and damaging the LiSICon membrane during the lithium separation process, thereby extending membrane lifespan
Solution Approach 2:
The invention introduces intermediate purification stages between the feed source and the membrane separation process. These intermediate systems act as protective barriers that remove harmful impurities before they can contact the sensitive LiSICon membrane, allowing the membrane to operate in a cleaner environment and maintain its integrity for longer periods
3Quantity of substance
If conventional electrolysis is used without controlled flow conditions, then lithium hydroxide can be produced, but impurity deposition on the membrane reduces permeance and efficiency
Solution Approach 1:
The patent implements dynamic flow control systems that continuously adjust the flow rate and velocity of the feed through the electrochemical cell. By maintaining optimal flow conditions, the system prevents impurities from settling and depositing on the membrane surface, ensuring that lithium ions can continuously pass through the membrane with high permeance and maintaining consistent production efficiency
Solution Approach 2:
The invention ensures continuous operation of the electrochemical cell with constant feed flow and periodic flushing mechanisms. This continuous action prevents impurity accumulation on the membrane by constantly moving the feed through the system, thereby maintaining high membrane permeance and avoiding interruptions in lithium hydroxide production
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process achieves high permeance and economic viability by preventing impurity deposition on the membrane, extending its lifespan and reducing energy consumption, while producing lithium hydroxide of sufficient purity for battery production.
Implementation Method 1
the flat membrane contains an inorganic material which has conductivity for Li-ions and which is electrically insulating
Implementation Method 2
electrochemical production of hydrogen and lithium hydroxide
Implementation Method 3
supplying the electrochemical cell with an electrical voltage U obtained from the electrical voltage source in such a way that an electrical current I flows between anode and cathode
Implementation Method 4
the continuous supply of the feed to the first compartment and the continuous removal of the wastewater from the first compartment result in a first flow which flows at an overflow velocity CFV through the first compartment along the flat membrane
Data Source
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AI summary
The invention is based on the objective of providing a process for the electrochemical production of LiOH from Li+-containing water using an electrochemical cell with a LiSICon membrane, which can also be operated economically on an industrial scale. In particular, the process should exhibit high energy efficiency and achieve a long membrane service life even when the feed material used contains impurities that are detrimental to LiSICon materials. This objective is achieved by adjusting the flow conditions in the anodic compartment of the electrochemical cell such that the anolyte flows along the membrane at a certain minimum flow velocity.